What issue did the jungle, by upton sinclair, expose?

It's most likely choice a, it makes the most sense in my opinion.

To solve their problems, mesopotamians used irrigation, a way of supplying water to an area of land. to irrigate their land, they dug out large storafe basins to hold water supplies these ditches brought water to the feilds. to protect their feilds from flooding, farmers built up the banks of the tigris and euphrates.hope ths !